Ingersoll-Rand 7120 - Manual (Page 69)

FAULT FINDING
66
7/120 (P425AWIR), 9/110 (XP375AWIR), 10/105 (HP375AWIR), 14/85 (VHP300AWIR),
7/170 (P600WIR), 10/125 (HP450WIR), 14/115 (VHP400WIR)
Compressor
overheats. Low oil level. Top up the oil level and
check for leaks.
Dirty or blocked oil
cooler. Clean the oil cooler
fins.
Incorrect grade of
oil. Use Ingersoll–Rand
recommended oil.
Defective by-pass
valve. Check the operation
of the element and
replace if necessary.
Recirculation of
cooling air. Move the machine to
avoid recirculation.
Reduced cooling air
from fan. Check the fan and the
drive belts. Check for
any obstruction inside
the fan cowl.
Excessive oil
present in
the
discharge Blocked scavenge
line. Check the scavenge
line, drop tube and
orifice. Clean and
replace.
air.
Perforated separator
element. Replace the
separator element.
Pressure in the
system is too low. Check the minimum
pressure valve.
Safety valve
operates. Operating pressure
too high. Refer to SPEED AND
PRESSURE RE-
GULATION AD-
JUSTMENT in the
MAINTENANCE sec-
tion of this manual.
Incorrect setting of
the regulator. Adjust the regulator.
Faulty regulator. Replace the regulator.
Inlet valve set
incorrectly. Refer to SPEED AND
PRESSURE
REGULATION
ADJUSTMENT in the
MAINTENANCE
section of this
manual.
Loose pipe/hose
connections. Check all pipe/hose
connections.
Faulty safety valve. Check the relieving
pressure. Replace
the safety valve if
faulty.
DO NOT
ATTEMPT A
REPAIR.
Oil is forced
back into the
air filter. Incorrect stopping
procedure used Always employ the
correct stopping
procedure. Close the
discharge valve and
allow the machine to
run on idle before
stopping.
Faulty inlet valve. Check for free
operation of the inlet
valve(s).
Machine
goes to full
pressure
when
started. Faulty load valve. Replace the valve.
Machine fails Faulty load valve. Replace the valve.
to load when
the load
Faulty switch. Test switch
the load
switch is
pressed.
Loose pipe/hose
connections. Check all pipe/hose
connections.